holiday barge/ car carrier.

Discussion in 'Boat Design' started by whitepointer23, May 21, 2015.

  1. whitepointer23

    whitepointer23 Previous Member

    A project I have been I have been thinking about for a while is to build a landing craft style barge after I finish my current yacht project. Just after ideas for a plywood epoxy hull. Accomodation for 2. Cabin around 12 ft long plus room for a car on deck . Small wheelhouse above Cabin. About 32ft x 9ft beam. I have a 40 hp diesel with 2.1 box. some sort of shallow water drive . I thought about toms lifting drive but that doesn't have any reverse thrust in shallows because the prop is pushed up behind the transom. So maybe a stern similar to rescue minor. What speed could I expect with 40 hp and what weight will a flat bottom support in those dimensions. It does not to be trailable or folding. I am only interested in wood epoxy to avoid corrosion issues on a moored vessel. Thanks in advance.
     
  2. tom kane
    Joined: Nov 2003
    Posts: 1,768
    Likes: 49, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    holiday barge/car carrier.

    Cam.a.propulsion is a retractable shaft drive and is not fixed in one position
    and can be raised and lowered from the helm, up behind the transom or down 20 degree shaft angle.
    It can be built in a design that suits, and you can add your own ideas.
     
  3. whitepointer23

    whitepointer23 Previous Member

    I think your drive is excellent tom but I can't see how it can reverse when the prop is pushed up in shallows. I am thinking about sneaking right up to the beach for camping so there may only be a foot or so of water at the transom but I don't know how much the barge will draw yet. I am waiting on someone to give me a rough idea based on the dimensions I have given. If your system can operate in reverse then it would be ideal.
     
  4. tom kane
    Joined: Nov 2003
    Posts: 1,768
    Likes: 49, Points: 58, Legacy Rep: 389
    Location: Hamilton.New Zealand.

    tom kane Senior Member

    holiday barge/car carrier.

    With a boat that can float in 4 to 6 inches of water you can have half of the prop below the bottom of the boat in 10 to 12 inches of water, and with a reverse box there is no problem and usually some one is available to give a push if needed.

    The Pivotal Drive finds it`s own depth in the water because it can slide up and down by it`s self when the s keg touches the bottom or it can be set at any desired point.
     

    Attached Files:

  5. whitepointer23

    whitepointer23 Previous Member

    Thanks tom. I will have another look at your gallery.
     
  6. whitepointer23

    whitepointer23 Previous Member

    can anyone give me an estimate on carrying capacity and draft for this barge please.
    .
     
  7. waikikin
    Joined: Jan 2006
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    Location: Australia

    waikikin Senior Member

    well.... if your wl beam was say 2.5 & wl about 8.5.... & the bottom flat every 100mm imersion in fresh would give about 2.1 tonne & a bit more in salt..., considering the power mentioned you might want to cut away the bottom a bit at stern for waterflow so a bit less.... then as the swim end fwd took up a bit you'd get more so maybe at 4.7 tonne with the car? on board say 250mm?

    Have a look for uslc online for some guidance on timber scantlings as a start, tabular so easier to interpret.

    Jeff.
     
  8. whitepointer23

    whitepointer23 Previous Member

    Thanks jeff. Thats pretty good. The car is under 2 ton and the cabin won't be a lot. Perkins and fuel and batterys about 600 kg.
     
  9. Village_Idiot
    Joined: Oct 2007
    Posts: 382
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    Location: USA

    Village_Idiot Senior Member

    Here is the math so that you can work your own calculations:

    One cubic foot displacement in freshwater = 62.4 lbs. In saltwater, 64 lbs.

    For an example, a 32'×9' perfectly rectangular barge (32x9 at waterline), your buoyancy would be 17971.2lbs at 12 inches draft, or just under 1500 lbs per inch of draft in freshwater. Now, from those numbers, you must subtract the total weight of the barge (including all necessary equipment), to get your net buoyancy/draft numbers. For safety reasons (reserve buoyancy in gale-force seas), you will want your safe load capacity to be roughly one-third (rule of thumb) of your maximum calculated capacity after subtracting inherent barge weight. This number can be modified with proper engineering calculations and/or empirical vessel testing.
     

  10. whitepointer23

    whitepointer23 Previous Member

    Thanks v.
     
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